Dolly-bar.



N0. 726,080. PTENTED APR. 21, 1903. J. MAGBETH & vL. T. JOHNSON.

DOLLY BAR l APPLIOATION FILED D120. 26. 1901.

N0 MODEL.

. I II 1 ATTORNEYv W/ TN E SSE S UNITED STATESV PATENT @Fries JAMES MACBETH AND LAwREonTfJoHNsoN, or BUFFALO, NEW YORK.

DoLLY-BAR.A

SPECIFICATION forming part ot- Letters Patent No. 726,080, dated April 21, 1903. Application filed December 26, 1901. Serial No. 87,386. (No model.)

T0 @ZZ whom t may con/cern." Y

Be it known that we, JAMES MACBETH and LAWRENCE T. JOHNSON, ci tizens ofthe United States, and residents of Buffalo, county ot' Erie, and State of New York, have invented a new and useful Improvement in Dolly-Bars, of which the following is a specilicatiomthe principle of the invention being herein explained andthe best mode in which We have contemplated applying that principle, so as to distinguish it from other inventions.

Our invention relates to means for holding rivets or the like in place While being upset or secured.

The object of such invention is to provide a portable device of said character ofY improved construction, whereby it may be etticaciously applied for use on I-beams or channel-bars in bridge-buildingor other constructions where the use of stationary devices of this character is prohibited, such portable devices as so especially applied being technically termed dolly-bars.

The invention consists of means hereinafter fnlly'described, and specifically setforth in the claims.

The annexed drawings and the following description set forth in detail certainmechanism embodying theinvention, such'dismechanical forms in whichY the principle ot the invention may be used.

In said annexed drawings, Figure I represents a top plan view of a device embodying our invention as particularly designed for holding rivets while being upset, Fig. II represents a vertical axial cross-sectionof such device, with the exception of a portion which is shown in elevation.

The main or body portion A consists of a portable structure of a size and weight such that it may be readily carried about and placed as desired byl hand, such structure being of T shape, as shown, and formed with two cylindrical bores a and b, respectively, the aXis of bore ct'being located at right angles relatively to the axis of bore l), the lat.- ter bore forming a pressure-chamber. The two bores have connection with one another through the medium of a channel c, located at the inner end of bore b, as shown. In each end of bore d and upon either side of chanbeam or bar, as shown inFig. II.

nel c is located a plunger D D, the movement of each of which is limited by means of a groove ,formed in each plunger, and a stud a', projecting from the inner surfaceof bore a. The inner end-of each plunger is provided with suitable packing d for eecting air-tight connection. The outer end of each plunger is formed with a recess d2 for receiving the head of the rivet to be held.

Arranged tandem with the bore b of the pressure-chamber is a bore e of a cylinder E. Two pistons A and-E operate in said pressure-chamber and cylinder, respectively, and are connected andv mountedupon a common piston-rod F, the length of such rod being such as to cause the pistons to occupy like ends of their respective strokes simultaneously. Intermediately of the piston E and the opposite end of the cylinder is located a helical spring G, which normally holds the two pistons at the ends of their outward strokes, as shown in Fig. Il, and at the outer head of cylinder E is formed a channel e', to which may be connected a fluid-pressure connection e2.

In operating the above-described device and applying it for userin connection with I- beams and channel-bars, for which use the device is'particularly adapted, the device is placed so asto bring one ofthe plungers imrnediately below the rivet to be operated upon,

substantially parallel with "the web of the A Fluid under pressure being now admitted into the outer end of cylinder E, pistons A and E are pushed forward against the action of spring G, whereby said spring is compressed and the plungers D D forced outwardly by the movement of the air in b until the one contacts the rivet and the other the opposite flange of the beam or bar. On continuing to admit the iiuid under pressure the air in chamber-bore b Aand bore a is compressed, thus rmly pressing the plungers against rivet and flange. The pressure of the admitted uid is of an intensity sufficient to properly hold the rivet while being upset. Upon completion of the upsetting operation the liuid pressure is turned oft from the cylinder, lwhereupon the compressed spring G returns the pistons quickly to their initial positions, therebyrelieving the pressure upon the plungers. and

permitting the latter to return to their normal positions.

Two plungers are preferably provided, as shown, whereby the tool is made double-ended and a greater range of travel given with a given length of travel of one plunger than would be the case were but a single plunger employed. A device embodying the principle of my invention and employing but one plunger may, however, be constructed, as will be readily understood from the foregoing description.

Compressed air is preferably used asa motive agent in actuating the piston E.

Other lnodes of applying the principle of our invention may be employed instead of the one explained, change being made as regards the mechanism Aherein disclosed provided the means stated by any one of the following claims or the equivalent of such stated means be employed.

lVe therefore particularly point out and distinctly claim as our invention- 1. A dolly-bar consisting of a portable body structure provided with a lnessurecharnber in its main portion, a barrel located transversely relatively to said main structure portion, said barrel being provided with a bore passing throughout its length; two plungers in opposite ends of said bore adapted to be moved out of said barrel, a piston in said chamber, and means for actuating said piston to create pressure in said chamber, the latter being connected with said bore, whereby said plungers may be actuated outwardly from said barrel in opposite directions.

2. A dolly-bar consisting of the combination of the portable body structure having the pressure-chamber l), the cylinder E, pistons E and A connected upon one common piston-rod, the spring G, the bore a, and the plungers D D, bore a and chamber b being connected whereby pressure from chamber b may be communicated to bore a, and a suitable inlet for introducing Huid-pressure into cylinder E.

Signed by us this 15th day of November, 1901.

JAMES MACBETI'I. LAWRENCE T. JOHNSON.

Attest:

IIARRY N. KRAFT, WINDSOR DOHERTY. 

